The invention concerns a process for construction of an underground structure, particularly a tunnel, a subway station, in particular in loose soil, as well as the structure thus obtained.
It is already known, particularly from Belgian Pat. No. 864.136 filed by the applicant, to construct such structures by means of excavations which are timbered and covered with concrete constituting the vertical walls of the structure and of pipes driven into the soil parallel to said walls and intended to form the roof of the latter.
In another process the pipes forming the roof are driven perpendicular to the longitudinal axis of the structure and consequently perpendicular to the vertical walls.
In the present state of the art these pipes are driven starting from a longitudinal gallery made by the known process of digging and shoring.
These processes present certain disadvantages. Particularly, the construction putting these processes into practice can prove to be relatively long. Besides, settling can be produced in the foundations of houses or at the level of the surface installations such as roads, railroads, under which the structure is constructed. Finally, the known processes pose problems concerning the safety of the works.